Power detectors are circuits which are useful in a wide variety of applications, e.g. in receivers in wireless communications systems, in radar systems or in TV sets.
With the increase in data speeds, the demands for lower response times for power detectors also increase. Conventional power detectors which usually comprise a transistor or a diode, together with a low pass filter, are usually unable to provide the desired fast response times, especially with a stable output signal.
Another kind of power detector which has been proposed in order to deliver fast response times is a differential or mixer based power detector. However, such power detectors require the use of a balun which usually comprises reactive components, such as, for example, coupled transmission lines. Such reactive components may degrade the response times, and may also cause distortions of the output signal and limit the power detector's frequency bandwidth.